int maxpix = 120;  // maximálna poloha v pixeloch
int stpx = 27;  // lineárna závislosť medzi krokmi a bodmi
int stlf = 61;  // množstvo krokov na posunutie o jeden pixelový riadok
int offset = 1;  // offset od nominálnej hodnoty
int sthm = 600;  // množstvo krokov po "homingu"
int duty = 18; // pracovný cyklus 1 pixelu

byte naTlac[130];  // alokované bajty (čislo v hr. zátvorkách sa musí rovnať hodnote maxpix)

long step = 0;  // kroky motora tlačovej hlavy
long tarstep = 0;  // cieľová pozícia motora tlačovej hlavy
long printpix = 0; // pixel na tlač
long pixel = 0;  // horizontálna poloha v pixeloch
long stplnfdamnt = 0;  // relatívne množstvo krokov na posuv papiera o riadok
byte val = 0;  // hodnota čítaná z array naTlac
int toprint = 0; // má sa tlačiť? Platí len pre jeden riadok pixelov
int printdir = 0;  // smer tlače
unsigned int clearing = 0;
long linfdstep = 0;  // množstvo krokov na posuv riadku
byte fdp = 0;
int carrstepdelay = 30;  // čas medzi polpulzmi kroku pre posuv tlačovej hlavy

void setup() {

  pinMode(2, OUTPUT);  // stepper 1 dir
  pinMode(3, OUTPUT);  // stepper 1 step
  pinMode(7, OUTPUT);  // stepper 2 dir
  pinMode(4, OUTPUT);  // stepper 2 step
  pinMode(5, OUTPUT);  // tlačiaca ihlička

  pinMode(6, INPUT_PULLUP);  // koncový kalibračný spínač
  pinMode(A1, INPUT_PULLUP);  // posuv o 5mm vpred (400 krokov)
  pinMode(A2, INPUT_PULLUP);  // posuv o 5mm dozadu (400 krokov)

  digitalWrite(7, HIGH);

  Serial.begin(57600);

  Serial.write(0x0A);  // tento riadok môžete vynechať

  shlulls();

}

void loop() {

  if (Serial.available()) {

    fdp = Serial.read();

    if (fdp == 49) {
      naTlac[printpix] = 1;

      if (printpix >= maxpix - offset) {
        Serial.write(0x13);
        printpix = 0;
        toprint = 1;
      }
      else {
        printpix = printpix + 1;
      }
    }

    if (fdp == 48) {
      naTlac[printpix] = 0;

      if (printpix >= maxpix - offset) {
        Serial.write(0x13);
        printpix = 0;
        toprint = 1;
      }
      else {
        printpix = printpix + 1;
      }
    }

  }

  if (fdp == 50) {
    fdp = 0;
    stepMoveBlankLineForwards();
  }

  if (fdp == 51) {
    fdp = 0;
    stepMoveBlankLineBackwards();
  }

  if (toprint == 1 && printdir == 0) {
    stepMovePrint();
  }

  if (toprint == 1 && printdir == 1) {
    stepMovePrintReverse();
  }

  if (digitalRead(A1) == LOW) {
    delay(250);
    stepMoveBlankLineForwards();
  }

  if (digitalRead(A2) == LOW) {
    delay(250);
    stepMoveBlankLineBackwards();
  }

}

void stepMovePrint() {  // tlačenie jedného riadku
  tarstep = pixel * stpx;
  digitalWrite(2, LOW);

  if (toprint == 1) {
    while (pixel <= maxpix - 1) {
      tarstep = pixel * stpx;
      val = naTlac[pixel];
      while (tarstep > step) {
        tarstep = pixel * stpx;
        digitalWrite(3, HIGH);
        delayMicroseconds(carrstepdelay);
        digitalWrite(3, LOW);
        delayMicroseconds(carrstepdelay);

        if (tarstep - step <= duty) {
          digitalWrite(5, LOW);
        }

        else {
          digitalWrite(5, val);
        }

        step = step + 1;
      }

      if (tarstep <= step) {
        pixel = pixel + 1;
      }

    }

  }
  toprint = 0;
  digitalWrite(5, LOW);
  printdir = 1;
  stepLinefeed();
}

void stepLinefeed() {
  digitalWrite(7, HIGH);
  stplnfdamnt = stlf;

  while (stplnfdamnt >= 1) {
    digitalWrite(4, HIGH);
    delayMicroseconds(60);
    digitalWrite(4, LOW);
    delayMicroseconds(60);
    stplnfdamnt = stplnfdamnt - 1;
  }
  printpix = 0;
  clearing = 0;

  for (int i = 0; i <= maxpix; i = i + 1) {
    naTlac[i] = 0;
  }

  Serial.write(0x11);
  Serial.write(0x41);
}

void stepMovePrintReverse() {  // tlačenie jedného riadku
  tarstep = pixel * stpx;
  digitalWrite(2, HIGH);

  if (toprint == 1) {
    while (pixel >= 0) {
      tarstep = pixel * stpx;
      if (pixel > -1) {
        val = naTlac[pixel];
      }
      if (pixel == -1) {
        val = naTlac[0];
      }
      while (tarstep < step) {
        tarstep = pixel * stpx;
        digitalWrite(3, HIGH);
        delayMicroseconds(carrstepdelay);
        digitalWrite(3, LOW);
        delayMicroseconds(carrstepdelay);

        if (step - tarstep <= duty) {
          digitalWrite(5, LOW);
        }

        else {
          digitalWrite(5, val);
        }

        step = step - 1;
      }

      if (tarstep >= step) {
        pixel = pixel - 1;
      }

    }
  }
  digitalWrite(5, LOW);
  toprint = 0;
  printdir = 0;
  stepLinefeed();
}

void shlulls() {
  digitalWrite(2, HIGH);

  while (digitalRead(6) == HIGH) {
    digitalWrite(3, HIGH);
    delayMicroseconds(250);
    digitalWrite(3, LOW);
    delayMicroseconds(250);
  }

  while (step <= sthm) {
    digitalWrite(2, LOW);
    digitalWrite(3, HIGH);
    delayMicroseconds(250);
    digitalWrite(3, LOW);
    delayMicroseconds(250);
    step = step + 1;
  }

  tarstep = 0;
  step = 0;
  pixel = 0;
  printpix = 0;

}

void stepMoveBlankLineForwards() {
  linfdstep = stlf * 15;
  digitalWrite(7, HIGH);
  while (linfdstep > 0) {
    digitalWrite(4, HIGH);
    delayMicroseconds(60);
    digitalWrite(4, LOW);
    delayMicroseconds(60);
    linfdstep = linfdstep - 1;
  }
}

void stepMoveBlankLineBackwards() {
  linfdstep = stlf * 15;
  digitalWrite(7, LOW);
  while (linfdstep > 0) {
    digitalWrite(4, HIGH);
    delayMicroseconds(60);
    digitalWrite(4, LOW);
    delayMicroseconds(60);
    linfdstep = linfdstep - 1;
  }
}